Increase of entanglement by local PT -symmetric operations

TL;DR

This paper demonstrates that local PT-symmetric operations can increase entanglement in bipartite quantum states, challenging the traditional understanding that entanglement cannot be increased by local actions.

Contribution

It introduces the novel idea that local PT-symmetric operations can enhance entanglement, violating the standard entanglement monotonicity principle.

Findings

Concurrence of bipartite states can be increased locally.

PT-symmetric operations violate entanglement monotonicity.

Bell-CHSH and steering inequalities confirm the phenomenon.

Abstract

Entanglement plays a central role in the field of quantum information science. It is well known that the degree of entanglement cannot be increased under local operations. Here, we show that the concurrence of a bipartite entangled state can be increased under the local PT -symmetric operation. This violates the property of entanglement monotonicity. We also use the Bell-CHSH and steering inequalities to explore this phenomenon.